Vacuum cleaner



Dec. 19, 1933. I LJUNGQUIST I 1,940,260

' VACUUM CLEANER Filed Dec. 9. 1929 V TOR J a; BY

Patented Dec. 19, 1933 PATENT OFFICE VACUUM CLEANER Gustaf Liungquist, Stockholm, Sweden, assignor to Elektriska A/B. Volta, Stockholm, Sweden, a corporation of Sweden I Application December 9, 1929, Serial No. 412,598,

and in Germany December 10, 1928 2 Claims. (Cl. 248-16) My invention relates to the vacuum cleaner art and has particular reference to vacuum cleaners of the portable domestic type in which a dust collector and an electric motor for driving 5 a fan are enclosed within a horizontally arranged casing.

One object of my invention is to provide supporting means for the fan motor unit which allow a resilient suspension of said unit, thus cushioning vibrations occurring therefrom and counteracting their transfer to the casing so that silent operation of the cleaner is made possible.

Another object of the invention is to provide supporting means which completely insulate. the motor and the current conducting elements of the apparatus from the casing thereof. This and other objects and advantages of my invention will be apparent from the following specification considered in connection with the accompanying drawing which forms a part thereof and on which:

Fig. 1 is an elevational view of a vacuum cleaner embodying a preferred form of my invention, and

Fig. 2 is an enlarged view in cross-section o the rear end of the cleaner.

In the figures, reference character 10 designates the main cylindrical body portion of the casing of the cleaner whichis supported on runners 11. The casing is provided with a handle 12 and encloses a dust bag 10a of known type, a fan 13, andmotor 14 driving said fan. The casing comprises removable caps 15 and 16 atthe ends thereof, having apertures constituting the air inlet and air outlets respectively, to which apertures hoses or tools to be used during operation of the cleaner can be connected,

. bers in the embodiment shown consist of-a conical spiral spring 20 engaging the unit at one end and buffers 21 of any resilient material, such as rubber or the like, engaging the unit at the other end. In the assembled position of the parts, as shown in Fig. 2, the spring 20 and the buffers 21 are preferably under axial stress. The weight of the motor-fan unit acts downwardly and places these supporting members also under transverse stress. The resiliency of these members and the values of axial stress in assembled position are determined by the weight of the motor-fan unit. By suitably constructing the parts with regard to this weight, a cushioned support may be obtained which is highly resilient and efficiently cushions vibrations of the inotor. In spite of its resilience, the arrangement is very stable since the radial or transverse stresses produced in the resilient members, when the motor-fan unit moves laterally of its neutral position, increase rapidly with the extent of displacement from neutral position and these stresses tend to bring the motor-fan unit back to neutral position. This characteristic is alterable by providing members'of different axial stress when assembled.

In the example shown, in which these axially located resilient members are arranged at both ends of the motor fan unit and consist, as above mentioned, of a spiral spring 20 and resilient buffers 21, the chamber of the'casing in which these parts and the motor-fan unit are located is so designed that, when the parts are assembled, the spiral spring 20 presses said unit against the buffers. 21 and the desired axial stress in said supporting members is produced. It will be seen that the flexibility of this supporting arrangement has its highest value when the motor-fan unit rests in its neutral position and that, when, due to vibrations, the unit is moved from this position in radial direction, increasing radial stresses will occur in the supporting members tending to bring the unit back. The supporting members also provide flexibility in axial direction.

I have found it very advantageous to produce the above explained effect by means of spiral springs preferably centrally arranged as shown at the rear end of the motor. v

Between cap 18 and casing 10 is arranged packing means 29 suitably consisting of felt or rubber, but this packing is not for the purpose of supporting the motor but'is provided only to prevent pressure equalization between the chambers in front of and behind the fan 'respectively, i. e. to prevent air which has been drawn through opening 19 by fan 13 from flowing .backinto the chamber where dust bag 10a is located. The spiral spring 20, which is conically formed for obtaining increased stability,

abuts with its end of small diameter against the front end of cap 18 is an annular depression 28' with which bufiers 21 engage in order to prevent relative radial movement betweenthe motor fan unit and said buifers As will be evident from the above, the whole motor-fan unit is electrically insulated from the casing of the apparatus partly by means of buffers 21 and partly by means of members 29 and 24. For this purpose bolts 26 are sunk into buflers 21 so that their heads will not come into contact with cap 18.

What I claim is:

1. In avacuum cleaner, a casing, a motor-fan unit in said casing, said motor-fan unit being spaced axially from the casing at one end, and

a plurality of members for supporting said unit in said casing including a conical spiral spring in said space stressed axially with respect to the spring between said unit and said casing and stressed transversely with respect to the axis of the spring due to the weight of said unit, the small diameter end of the spring being adjacent said unit and the large diameter end thereof being adjacent the casing, said ends of the spring being fixed against radial movement with respect to the motor-fan unit and the casing, respectively.

2.'In a vacuum cleaner, a cylindrical casing, means for supporting said casing horizontally above a horizontal surface, a motor-fan unit axially disposed in said casing, said motor-fan unit being spaced from said casing at each end, resilient supporting means between one end of said unit and the casing, a spiral spring in the space between the other end or said unit and the casing, and a seating member for said spring made of insulating material, the ends of the spring being fixed against radial movement with respect to the motor-fan unit and the casing, respectively.

, GUSTAF LJUNGQUIST. 

